1. Field of the Invention
This invention relates to a small animal breeding apparatus in which small animals such as mice and rats for use in experiments are bred.
2. Description of the Prior Art
An apparatus shown in FIG. 3 through FIG. 5 is known as a conventional small animal breeding apparatus. This small animal breeding apparatus has a frame 2 of rectangular parallelepiped shape made of angle bars, shelves 3 which divide the interior space of the frame 2 into a plurality of vertically arranged stages, a plurality of breeding spaces 4 which are formed above the shelves 3, respectively, breeding cages 5 each of which is placed in each breeding space 4, and air exhaust holes 8 which open at the rear of each breeding space 4.
In the conventional small animal breeding apparatus 1 constructed as above, when the breeding cages 5 are placed in the breeding spaces 4 and an exhaust system not shown is operated, air is taken from the front of each breeding space 4, sent to the inside of the space 4, and then sucked into an exhaust pipe through each exhaust hole 8. Thus, air fouled by the small animals in the breeding cages 5 can be discharged.
In the above described conventional small animal breeding apparatus 1, a problem exists in that the breeding cages 5 are not fully ventilated, because the front side of each breeding space 4 is open, and fresh air taken into each space 4 from the front side of the frame under the sucking action by the exhaust hole 8 is sent to the rear of each space, while passing through the region above each breeding cage 5, and is directly discharged through the exhaust hole 8 without circulating in the interior of the cage 5. For this reason, foul air in each breeding cage 5 stagnates and is not discharged to the outside, and the breeding cage 5 is not sufficiently ventilated.
This invention is made to solve the above problem and its object is to provide a small animal breeding apparatus that can always keep air clean in the breeding cages.